Amazon deforestation: A dangerous future indicated by patterns and trajectories in a hotspot of forest destruction in Brazil.

In recent years, the loss of forest in the Brazilian Amazon has taken on alarming proportions, with 2021 recording the largest increase in 13 years, particularly in the Abunã-Madeira Sustainable Development Reserve (SDR). This has significant environmental, social, and economic repercussions globally and for the local communities reliant on the forest. Analyzing deforestation patterns and trends aids in comprehending the dynamics of occupation and deforestation within a critical Amazon region, enabling the inference of potential occupation pathways. This understanding is crucial for identifying deforestation expansion zones and shaping public policies to curb deforestation. Decisions by the Brazilian government regarding landscape management will have profound environmental implications. We conducted an analysis of deforestation patterns and trends up to 2021 in the municipality (county) of Lábrea, located in the southern portion of Amazonas state. Deforestation processes in this area are likely to spread to the adjacent "Trans-Purus" region in western Amazonas, where Amazonia's largest block of remaining rainforest is at risk from planned highways. Annual deforestation polygons from 2008 to 2021 were categorized based on occupation typologies linked to various actors and processes defined for the region (e.g., diffuse, linear, fishbone, geometric, multidirectional, and consolidated). These patterns were represented through 10 × 10 km grid cells. The findings revealed that Lábrea's territory is predominantly characterized by the diffuse pattern (initial occupation stage), mainly concentrated in protected areas. Advanced occupation patterns (multidirectional and consolidated) were the primary contributors to deforestation during this period. Observed change trajectories included consolidation (30.8%) and expansion (19.6%) in the southern portion of the municipality, particularly along the Boi and Jequitibá secondary roads, providing access to large illegal landholdings. Additionally, non-change trajectories (67%) featured initial occupation patterns near rivers and in protected areas, likely linked to riverine and extractive communities. Tailoring measures to control deforestation based on actor types and considering stages of occupation is crucial. The techniques developed in this study provide a comprehensive approach for Amazonia and other tropical regions.

Potential aboveground biomass increase in Brazilian Atlantic Forest fragments with climate change.

Fragmented tropical forest landscapes preserve much of the remaining biodiversity and carbon stocks. Climate change is expected to intensify droughts and increase fire hazard and fire intensities, thereby causing habitat deterioration, and losses of biodiversity and carbon stock losses. Understanding the trajectories that these landscapes may follow under increased climate pressure is imperative for establishing strategies for conservation of biodiversity and ecosystem services. Here, we used a quantitative predictive modelling approach to project the spatial distribution of the aboveground biomass density (AGB) by the end of the 21st century across the Brazilian Atlantic Forest (AF) domain. To develop the models, we used the maximum entropy method with projected climate data to 2100, based on the Intergovernmental Panel on Climate Change Representative Concentration Pathway (RCP) 4.5 from the fifth Assessment Report. Our AGB models had a satisfactory performance (area under the curve > 0.75 and p value < .05). The models projected a significant increase of 8.5% in the total carbon stock. Overall, the projections indicated that 76.9% of the AF domain would have suitable climatic conditions for increasing biomass by 2100 considering the RCP 4.5 scenario, in the absence of deforestation. Of the existing forest fragments, 34.7% are projected to increase their AGB, while 2.6% are projected to have their AGB reduced by 2100. The regions likely to lose most AGB-up to 40% compared to the baseline-are found between latitudes 13° and 20° south. Overall, although climate change effects on AGB vary latitudinally for the 2071-2100 period under the RCP 4.5 scenario, our model indicates that AGB stocks can potentially increase across a large fraction of the AF. The patterns found here are recommended to be taken into consideration during the planning of restoration efforts, as part of climate change mitigation strategies in the AF and elsewhere in Brazil.

Assessment of TerraClass and MapBiomas data on legend and map agreement for the Brazilian Amazon biome

Reliable environmental monitoring and evaluation require high-quality maps of land use and land cover. For the Amazon biome, the TerraClass and MapBiomas projects apply different methodologies to create these maps. We evaluated the agreement between land cover and land use maps generated by TerraClass and MapBiomas (Collections 2 and 3) for the Brazilian Amazon biome, from 2004 to 2014. Specifically, we: (1) described both project legends based on the LCCS (Land Cover Classification System); (2) analyzed the differences between their classes; and (3) compared the mapping differences among the Brazilian states that are totally or partially covered by the Amazon biome. We compared the classifications with a per-pixel approach and performed an evaluation based on agreement matrices. The overall agreement between the projects was 87.4% (TerraClass x MapBiomas 2) and 92.0% (TerraClass x MapBiomas 3). We analyzed methodological differences to explain the disagreements in class identification. We conclude that using these maps together without a properly adapted legend is not recommended for the analysis of land use and land cover change. Depending on the application, one mapping system may be more suitable than the other. (AU)

Deforestation dynamics in Brazil's Amazonian settlements: Effects of land-tenure concentration.

Brazil's Amazon deforestation is a major global and national environmental concern, and the ability to model and project both its course and the effect of different policy options depends on understanding how this process occurs at present and how it might change in the future. The present paper addresses one key factor in Amazon deforestation: land-tenure concentration in settlements. Brazil's policies for establishing and regulating settlement projects represent critical government decisions shaping the landscape in the 5 × 106 km2 Legal Amazonia region. We used remote-sensing data and information provided by the National Institute for Colonization and Agrarian Reform (INCRA) to evaluate the effect of land-tenure concentration in a settlement project (Projeto de Assentamento) located in a frontier area where cattle-ranching is expanding. We identified the actors and their deforestation patterns in the Matupi settlement in the southern part of Brazil's state of Amazonas. We spatially identified actors who concentrated "lots" (the parcels of land distributed to individual settlers) in 2011 and assessed whether the concentration was done by individual landholders or by "families" (where members merged their lots and the clearing was done together). Deforestation rates (1995-2011) were estimated for each type of actor and the trajectory of deforestation in the settlement (cumulative deforestation to 1994 and annual deforestation 1995-2016) was also analyzed. Concentrators occupied 28% (9653 ha) of the settlement and 29% of the lots (152 lots) analyzed; the numbers of lots concentrated ranged from two to ten. Concentrators of two lots and non-concentrators were the predominant actor types in the settlement. The mean annual clearing per landholding for concentrators of two lots (families: 4.1 ± 2.8 ha (mean ± SD); individuals: 5.1 ± 4.6 ha) was greater than for non-concentrators (1.7 ± 1.2 ha), despite their having similar patterns of small clearings. Concentrators of three or more lots had mean annual clearing per landholding between 6.2 ± 12.2 ha and 23.9 ± 38.7 ha and, the pattern of patches cleared per year >34 ha in area was predominant. The deforestation rate per lot was higher among concentrators as compared to non-concentrators, showing that lot concentration speeds deforestation. Analysis of deforestation patterns helps to better understand the process of lot concentration by spatially identifying the predominant patterns of each type of actor. The approach used in our study could assist authorities in identifying and monitoring land-tenure concentration in settlements. Agrarian-reform policymakers need to monitor this process, since it speeds deforestation in Amazonian settlement projects, as well as undermining the social objectives of the agrarian-reform program.

Comunidades ribeirinhas como forma socioespacial de expressão urbana na Amazônia: uma tipologia para a região do Baixo Tapajós (Pará-Brasil) / Riverine communities as socio-spatial units of the urban process in Amazon: a typology for the lower Tapajós River (State of Pará, Brazil) / Comunidades ribereñas como forma socioespacial de expresión urbana en la Amazonia: una tipología para la región del Baixo Tapajós (Pará-Brasil)

O fenômeno urbano na Amazônia contemporânea se estende pelo território e se estrutura por diversas formas socioespaciais, tais como as comunidades locais, que, ao formarem redes urbanas incipientes, têm características particulares definindo sua importância na estruturação do território regional. Neste artigo, é proposto o uso de técnicas quali-quantitativas para definir uma tipologia para as comunidades ribeirinhas do Baixo Tapajós (Pará): variáveis descritoras, obtidas por questionários de campo aplicados a 62 comunidades, entre Santarém e Itaituba, e submetidas à estatística multivariada. A partir da análise de componentes principais para 30 variáveis e agrupamento hierárquico, cinco grupos de comunidades foram identificados e descritos; resultado considerado consistente com as observações de campo. Variáveis relacionadas principalmente ao uso da terra e à infraestrutura condicionaram esta classificação. Comunidades em unidades de conservação, independente da localização na margem do Rio Tapajós, apresentaram situação distinta das demais, sendo que a presença do Estado, suportando programas governamentais, mostrou-se fundamental para manutenção de todas as comunidades.

The phenomenon of urban growth in the Amazon can be seen throughout the territory today and is structured into many different sociospatial forms. One such form consists of local communities, which, as they develop incipient urban networks, show specific characteristics that define their importance in the structuring of the territory throughout the region. In this paper we propose the use of quali-quantitative techniques for defining a typology for riverine communities along the Lower Tapajos River, in the State of Pará in northern Brazil. Descriptive variables were obtained through field-applied questionnaires in 62 communities between the towns of Santarém and Itaituba. The variables were then submitted to multi-variate statistics. On the basis of the analysis of the main components of 30 variables and hierarchical grouping, five groups of communities were identified and described, and the results were considered consistent with the field-based observations. Variables related mainly to the use of the land and to infrastructure conditioned this classification. Communities located in conservation units, regardless of exactly where they were located along the banks of the Tapajos river, were in a situation different from that of the other communities, since the maintenance of all of them depended on programs of the Pará State Government. The methodology presented can also be applied to other areas in the Amazon, provided that the specific characteristics of each area are taken into consideration. The typology proposed identifies the differences and presence of the communities in the regional space along the Lower Tapajos, and can be used for drawing up public policies addressed to local populations.

El fenómeno urbano en la Amazonia contemporánea se extiende por su territorio y se estructura por diversas formas socioespaciales, tales como las comunidades locales que, al formar redes urbanas incipientes, adquieren características particulares, definiendo su importancia en la estructuración del territorio regional. En este artículo, se propone el uso de técnicas cuali-cuantitativas para definir una tipología para las comunidades ribereñas del Baixo Tapajós (Pará): variables descriptoras, que se obtuvieron por medio de cuestionarios de campo aplicados a 62 comunidades, entre Santarém e Itaituba, y sometidas a la estadística multivariada. A partir del análisis de componentes principales para 30 variables y agrupamiento jerárquico, se identificaron y describieron cinco grupos de comunidades; el resultado fue considerado consistente con las observaciones de campo. Variables relacionadas principalmente al uso de la tierra y a la infraestructura condicionaron dicha clasificación. Comunidades en unidades de conservación, independientemente de la localización en la orilla del río Tapajós, presentaron una situación distinta de las demás; la presencia del Estado, apoyando programas gubernamentales, se mostró fundamental para el mantenimiento de todas las comunidades. La metodología presentada se puede aplicar a otras áreas en la Amazonia, siempre que se consideren las especificidades regionales. La tipología propuesta identifica las diferencias y la inserción de las comunidades del Baixo Tapajós en el espacio regional y se puede utilizar en el diseño de políticas públicas dirigidas a las poblaciones locales.

Estimativa de área de vegetação secundária na Amazônia Legal Brasileira / Estimation of secondary vegetation area in the Brazilian Legal Amazon

A vegetação secundária tem funções relevantes para os ecossistemas, tais como a fixação de carbono atmosférico, a manutenção da biodiversidade, o estabelecimento da conectividade entre remanescentes florestais, manutenção dos regime hidrológico e a recuperação da fertilidade do solo. O objetivo deste trabalho é, através de uma abordagem amostral, estimar a área ocupada por vegetação secundária na Amazônia Legal Brasileira (AML) em 2006. A amostragem se baseia em uma abordagem estratificada pelo grau de desflorestamento das cenas LANDSAT-TM que recobrem a AML. Foram selecionadas 26 cenas para o ano de 2006, distribuídas em sete estratos conforme o percentual de desflorestamento, nas quais foram mapeadas as áreas de vegetação secundária a partir de técnicas de classificação de imagens. Foi desenvolvido um modelo multivariado de regressão para estimar a área de vegetação secundária utilizando como variáveis independentes a área de desflorestamento, a área de hidrografia, a estrutura agrária, e área das unidades de conservação. A análise de regressão encontrou um R2 ajustado de 0,84 , e coeficientes positivos para a proporção de hidrografia na imagem (2,055) e para a estrutura agrária (0,197), e coeficientes negativos para o grau de desflorestamento na imagem (-0,232) e para a proporção de Unidades de Conservação na imagem (-0,262). O modelo de regressão estimou uma área de 131.873 km² de vegetação secundária para o ano de 2006. Aplicando uma simulação Monte Carlo foi estimada uma incerteza de aproximadamente 12.445 km² para a área.

Secondary vegetation has many relevant functions to the ecosystems such as atmospheric carbon fixation , maintenance of biodiversity, establishment of connectivity among forest remnants, maintenance of hydrological regime, and restoration of soil fertility. The objective of this work is to estimate the area occupied by secondary vegetation in the Brazilian Legal Amazon (BLA) for 2006 using a sampling scheme. The sampling is based on a stratified approach according to the degree of deforestation observed in the 229 TM-Landsat scenes that cover the BLA. Thus, 26 scenes were selected for 2006 and distributed into seven strata, according to their degree of deforestation, in which secondary vegetation areas were mapped. A regression model was constructed to estimate secondary vegetation area in the remaining images using deforestation area, hydrographic area, agrarian structure , and area of conservation units, as independent variables. The regression analysis found an adjusted R2 of 0.84 and positive coefficients for the proportion of hydrography in the image (2.055) and for the agrarian structure (0.197), while negative coefficients for the degree of deforestation in the image (-0.232) as well as for the proportion of Conservation Unity(-0.262). Using the multivariate regression model, an area of 131,873 km² of secondary vegetation was estimated for the year of 2006. Applying a Monte Carlo simulation we estimated an uncertainty of approximately 12,445 km² .

Processos de ocupação nas novas fronteiras da Amazônia: o interflúvio do Xingu / Iriri / Occupation processes in the new Amazonian frontiers: the Xingu/Iriri interflow

Este trabalho apresenta os primeiros resultados do esforço conjunto de várias instituições, organizadas em torno da rede Geoma (Rede Temática de Pesquisa em Modelagem Ambiental da Amazônia) para avançar a compreensão dos novos padrões e processos de estruturação do território nas novas frentes no sul do Pará, analisando padrões de desmatamento e os processos que dão origem a esses padrões. Busca-se, aqui, produzir os subsídios necessários para o desenho de políticas públicas responsáveis, que não privilegiem um único aspecto do problema, como a abertura de estradas, por exemplo. Aponta-se, então, a partir desses primeiros resultados, que apenas uma solução integrada que procure estruturar os principais agentes e processos na cadeia produtiva seria possível para minorar os efeitos do desmatamento e nortear o desenvolvimento integrado para a região, com benefícios para a floresta e para as populações que ali vivem.